    // key  键名
    // val  键值
    // day  过期时间
    // path  存储路径
    function setCookie(key,val,day,path="/"){
        // var val = "a123123";

        if(day){   // 有过期时间
            var date = new Date();
            date.setDate(date.getDate()+day);
            document.cookie = key + "="+ encodeURIComponent(val) + ";expires=" + date.toUTCString() + ";path="+path;
        }else{
            document.cookie = key + "="+ encodeURIComponent(val) + ";path="+path;
        }
    }

    function getCookie(key){
        var cookie = document.cookie;
        // console.log(cookie);
        if(cookie){  //有cookie时
            var list = cookie.split("; "); 
            // console.log(list); //  ["user=a123123", "pwd=123123", "phone=17386141517", "email=1272071495@qq.com"]
            for(var i=0;i<list.length;i++){
                var item = list[i]; // "user=a123123", "pwd=123123",
                var name = item.split("=")[0];
                var val = item.split("=")[1];
                if(name === key){
                    return decodeURIComponent(val);
                }

            }
        }
        return ""; 
    }

    function delCookie(key){
        setCookie(key,"",-1);
    }


    function clearCookie(){
        var cookie = document.cookie;
        // console.log(cookie);
        if(cookie){  //有cookie时
            var list = cookie.split("; "); 
            // console.log(list); //  ["user=a123123", "pwd=123123", "phone=17386141517", "email=1272071495@qq.com"]
            for(var i=0;i<list.length;i++){
                var item = list[i]; // "user=a123123", "pwd=123123",
                var key = item.split("=")[0];
                delCookie(key)
            }
        }
        return ""; 
    }

